Question

如何找到两小时差异的平均时间？

这是我的变体，但输出不能仅按名称分组。

SELECT NAME, DATEDIFF(HOUR, START_DATE, END_DATE)
FROM [dbo].[DB1]
GROUP BY NAME, START_DATE, END_DATE

示例：

1 DAY
START_DATE 2017-05-02 05-00-00-000
END_DATE   2017-05-03 00-00-00-000
RESULT: 7 HOURS

2 DAY 
START_DATE 2017-05-02 07-00-00-000
END_DATE   2017-05-03 12-00-00-000
RESULT: 5 HOURS

AND AVG RESULT = 6

Answer 1

在子查询中生成DATEDIFF，然后平均：

SELECT
    [Name],
    AVG( [Time] ) AS AverageTime
FROM
(
    SELECT
        NAME,
        DATEDIFF( hour, START_DATE, END_DATE ) AS [Time]
    FROM
        dbo.DB1
    GROUP BY
        NAME,
        START_DATE,
       END_DATE
) AS subquery

Answer 2

你的意思是，

SELECT NAME, AVG(DATEDIFF(HOUR, START_DATE, END_DATE))
FROM [dbo].[DB1]
GROUP BY NAME

以小时为单位的两个日期的平均差异时间

2 个答案: